ERR4686 | Thermostat and Radiator Filler Plug - 300Tdi & V8 | Defender, Discovery
To check the stock of Genuine Parts before placing an order please use our Contact Us page
To check the stock of Genuine Parts before placing an order please use our Contact Us page
To check the stock of Genuine Parts before placing an order please use our Contact Us page
To check the stock of Genuine Parts before placing an order please use our Contact Us page
Land Rover Part Number: ERR4686 - Thermostat and Radiator Filler Plug (Plastic)
ERR4686 is a plastic thermostat housing and radiator filler plug used to drain, bleed and refill the cooling system. Fitted into the thermostat housing or the radiator, the plug provides the service access point for coolant changes and for removing trapped air during bleeding; it should be replaced if it becomes cracked or leaks.
Compatibility
- Defender (1987-2006) - 300Tdi (2.5L I4)
- Discovery 1 (1989-1998) - 300Tdi (2.5L I4)
- Range Rover Classic (1992-1994) - 300Tdi (2.5L)
- Range Rover P38 (1994-2001) - 4.0 V8 Petrol, 4.6 V8 Petrol
Frequently Asked Questions
ERR4686 is a plastic filler plug that provides the service point for draining, bleeding and filling the vehicle's cooling system. It is installed in the thermostat housing or radiator and should be checked during coolant service for signs of cracking, thread damage or leaks that would prevent correct bleeding or filling.
| Model | Variant |
|---|---|
| Land Rover Defender | 1987 - 2006 - 2.5L 300Tdi (Thermostat housing / Radiator) |
| Land Rover Discovery 1 | 1989 - 1998 - 2.5L 300Tdi (Thermostat housing) (From FA393361 to WA799999) |
| Land Rover Range Rover Classic | 1992 - 1994 - 2.5L TDi (Thermostat housing) (From JA610294) |
| Land Rover Range Rover P38 | 1994 - 2001 - 4.0 V8 Petrol; 4.6 V8 Petrol (Radiator and cooling system) |
If you are unsure of compatibility with your vehicle, you can also confirm by checking against your V.I.N. Simply reach out to us with your V.I.N and desired part number via our Contact page or use our Finding Part Numbers page.
Inspect the filler plug whenever the cooling system is drained or during routine services; replace it if it is cracked, the sealing surface is damaged, or if it leaks when the system is pressurised.
- C8 products are usually supplied by Britpart.
- Z8 products are normally supplied by Allmakes.
All products and accessories available on LRDirect.com come with a 2-year warranty.